


Demigod Island

by totallyunrelated



Category: H2O: Just Add Water, Percy Jackson and the Olympians & Related Fandoms - All Media Types, Percy Jackson and the Olympians - Rick Riordan
Language: English
Status: Completed
Published: 2019-04-20
Updated: 2019-04-20
Packaged: 2020-01-20 16:08:31
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,154
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18528487
Author URL: https://archiveofourown.org/users/totallyunrelated/pseuds/totallyunrelated
Summary: Percy's dad, Poseidon, sends him and Annabeth to Mako Island, where they become mermaids. Contains elements from H2O Mermaid Adventures. (I don't own any of the characters)(Originally posted on fanfiction.net under the same name)





	Demigod Island

"Are you sure this is the right place?" A whisper cut through the silent night, belonging to a blonde-haired girl with stormy gray eyes. She glanced at her partner, a few steps ahead of her, looking birdlike with his head cocked and his eyes closed. His sea-green eyes snapped open and looked at her. "I'm sure, Annabeth. This is the place my dad wanted us to go to."

They were paused at the entrance to what looked like a narrow tunnel in the mountain, having hiked up on the night of the full moon, just as Percy's dad, Poseidon, had instructed them to. Just after the Giant War, he'd sent them to Mako Island in Dolphin City, leaving only a cryptic message with instructions and a mysterious note saying that they'd truly 'belong to the sea' after this. They hadn't questioned him – after all, he was an all-powerful god and they really didn't want to get on his bad side, which Percy seemed to have a knack for – and instead here they were now. Annabeth glanced up at the night sky. It was much clearer here than it was in New York City, though nothing could compare to her home, Camp Half-Blood. "The moon's almost up," she hissed to Percy. "We'd better hurry."

He gave a barely perceptible nod, reached back and grasped her hand. The feel of his callused hand in hers was warm and familiar, and she felt herself relaxing a little. During their entire week at Mako Island, they hadn't seen a single monster, which was strange but a relief. They were taking a much-needed vacation after two wars.

Then they were sliding through the tunnel, and landed with a splash in a moonlit pool at the bottom of the volcano. Annabeth looked around in wonder. "It's beautiful," she breathed, a smile stretching over her face. She glanced over at her boyfriend, but he looked strange. His eyes were glazed and his lips were parted, his head turned up to the moon. What was stranger was that he was wet – Percy was a child of the sea, he had the ability to keep himself dry in water. Annabeth suddenly had a foreboding feeling. What was going on?

"Percy," she said nervously. " _Percy._ What's going on? Why do you look like that?"

He didn't respond. Instead, he grasped her hand tighter and said, " _Soon,_ " in an eerie, un-Percy-like voice. A shiver crept down Annabeth's spine, but she didn't argue further. She trusted Percy with her life – even if she wasn't sure if the person in front of her was really Percy anymore.

Just then, the moon rose fully over the cliff that had been blocking it, and a white light clouded Annabeth's vision. She felt a flash of searing pain in her legs and screamed. She could barely make out the silhouette of Percy's body beside her as she fell fully submerged into the water, blinking back tears. But just as quickly as the pain came, it was gone.

"Percy!" she gasped. "Are you okay?..." The words died in her throat as she took in Percy. He was … changed. He'd always been handsome before, but now his features looked chiseled, almost beautiful, and she felt a sudden surge of desire. She pushed it down.  _Now is not the time, Annabeth,_ she scolded herself. Her eyes traveled down his body and she suppressed a gasp. She could have sworn he was wearing a shirt a moment ago. Where'd it go? And his legs … or rather his  _lack_ of them. She was openly staring now. Where his legs should have been was a beautiful fishtail. She couldn't pinpoint what the exact hue was because it kept shifting, but she saw his scales were lined in subtle gold and silver, and the base colour was sea green … or blue … or aquamarine … She blinked, feeling dizzy, and let her eyes travel back up to his face. He was watching her in amusement, his messy black hair flopped over his eyes like always … and then she noticed it. Her jaw fell open. There, nestled on top of his hair, like it had always been there, was a silver crown with a trident engraved on it. Poseidon's symbol. She gasped. "What happened, Percy?" she asked, voice shaking. He was studying her, his gaze intent, and when his eyes met hers, she felt a sudden rush of love for this boy who had been through everything with her.

"We're part of the sea now," he answered cryptically. She frowned. "What? Do you mean the fact that you're now a mer… er… merman?" He laughed, and the sound warmed her heart. "Look at yourself, Annabeth," he answered, eyes twinkling. She did. She'd been too absorbed in Percy to notice, but her legs felt weird. She moved them, and then she saw it. Her very own mermaid tail, with silvery-gray scales, and as she gazed at her reflection in the water, she saw a pearl tiara nestled on her blonde curls, which were now hanging loose around her face. Then she noticed her own apparent lack of a shirt, and the sports bra she'd put on that morning had been replaced with a sparkling shell bra, which was surprisingly comfortable.

"My mother will kill me!" Annabeth cried, her brain finally becoming unstuck. "She'll never – she hates Poseidon – she'll disown me …"

Percy was laughing, and as she spun to glare at him, he held his hands up in surrender. "I don't think she'll cause any problems," he snickered. "She's probably … ah … too  _busy_ with my dad to care. I don't think she hates him anymore, anyhow," he added thoughtfully, that infuriating smirk still on his face.

His words dawned on her, and she stumbled back. " _Busy?_ What are they doing?" she asked sharply.

His eyes twinkled. "I don't think you want to know, Annabeth," he said. "Probably the same thing  _we_ were doing last night," he added cheekily in an undertone. She smacked him. "Ow! There's no one here, anyway," he said sullenly. Her cheeks flushed at the implication. "So they're … together … now?" she asked hesitantly. He shrugged. "I don't know. I think so. Sure looked that way when I IM'ed Dad," he muttered. Annabeth was sure her cheeks were red as a tomato now, but she didn't get to say anything more.

"Hey!" The voice came from the top of the cliffs, and they both spun to look. Three girls were silhouetted there against the moonlight, and they were running straight towards them. Annabeth's brain whirled. If they were mermaids now, they'd be treated as freaks the moment someone saw them. Even with the help of the mist, they had to hide. Now! She grabbed Percy's hand and attempted to drag him under the surface of the water, but he wouldn't budge. "Percy!" she hissed. "We can't let them see us!"

He sent her a reassuring glance. "It's okay," he said soothingly. "They're like us. They're mermaids, too. Changed in this very pool, I bet." She froze and turned to look at the three girls, who had reached the edge of the pool by now.

"Oh,  _no_ ," one of them, a girl with striking red hair, groaned. The other two shot her sharp looks, then all three dived into the pool. Annabeth gasped – she couldn't help it. Their legs had been replaced with tails the colour of their hair, and they were dressed the same way she was. She couldn't help the small flare of anger at the proximity of these three strangers to her boyfriend, and swam closer to him protectively.

"My name's Emma," the blonde girl offered cautiously. "And those are Cleo and Rikki. We're like you, too. Don't be scared," she added. "We can help you."

Percy flashed his award-winning smile at them, and Annabeth felt her jealousy spike, even though she knew it was irrational. Knew he was hers, and she was his, and nothing could change that. But she couldn't stop herself. "I'm Percy," he said, still smiling. "And that's my girlfriend, Annabeth." Annabeth smiled at them, feeling better now that Percy had introduced her as his girlfriend. "So what's the deal with this whole thing?" she asked, gesturing to her tail. Percy hadn't explained, and she wasn't quite sure he got it, either.

"This place is magic," one of the girls – was her name Cleo? – said. "If you happen to be here when there's a full moon, you'll be … transformed." Annabeth's Athenian brain whirled, trying to make sense of this. She hated when she didn't understand something.

"Whenever you touch water, you'll be transformed," Emma was saying. "And when you're dry again, you'll get your legs back." Percy looked thoughtful. "When we're dry?" he repeated. Then, faster than Annabeth could see, he was dry, and he had legs again. And his shirt. Where did that come from? She almost wished his shirt hadn't come back. She'd been enjoying the view. As if hearing her thoughts, he turned and winked at her, and she blushed.

The girls looked shocked. "How did you do that?" Rikki exclaimed with an envious glance. "What I wouldn't give to be able to do that," Emma muttered, and the other two nodded in agreement. Annabeth smiled to herself. She knew exactly how Percy had been able to do that – his Poseidon powers. But if they turned the minute they touched water, well, that would be troublesome. It wouldn't matter so much at Camp Half-Blood, where no one would bat an eye, but in the outside world? They'd be locked up in an aquarium, or maybe a laboratory, faster than they could blink. It wouldn't be much of a problem for Percy … but maybe she could get him to teach her.

"You also might have powers," Cleo was saying. At the mention of 'powers', Annabeth perked up. She'd always felt fairly useless among demigods – as a child of Athena, the only powers she had were her brain. She'd always envied those demigods with powers inherited from their parents, such as Percy with his powers over the sea or Thalia and Jason, children of Zeus, with their power over the sky. She'd often had to rely on her brain and her training to get out of sticky situations, whilst others such as Piper had their charmspeak. With powers, she'd just be that much better.

"What kind of powers?" she heard herself saying eagerly. Percy shot her an amused glance. He knew how much her lack of powers bothered her, but he always comforted her, saying she was the most valuable one out of the Seven, even if she was the only one without powers. He always made her feel stronger than she was.

"We'll show you," Emma said eagerly, diving beneath the surface of the water. Percy and Annabeth followed.

"Watch," Cleo said. She held her hands out in front of her and the water began to swirl. Percy watched with an unreadable expression, but Annabeth, knowing him too well, could see his excitement. Next, Emma held out her hands, and the water froze over. Then Rikki took over and the ice started to melt. "Now you try," said Rikki. She had an excited expression, and Annabeth realized that keeping this secret, without knowing anything about the supernatural, would have been hard. She felt a pang of sympathy towards these three girls. At least they had each other.

Percy was watching the show with a thoughtful expression, and Annabeth wondered which of his slew of powers he would choose to show. He had a wide variety of powers, but he couldn't possibly show all of them. She looked at her own hands. What power did she have, then?

Percy held his hands out in front of him, flexing them, looking uncertain. To anyone else, it would have looked genuine, but Annabeth knew him better than anyone else. Percy was a surprisingly good actor. He had an underlying veneer of confidence. Annabeth watched, holding her breath. She'd seen Percy's powers displayed numerous times, but she still found something breathtaking about it.

As Percy held his hands out, storm clouds darkened above them and soon Annabeth heard the sound of rain falling on the surface. She couldn't keep the surprised expression off her face. She hadn't known he could do that.  _Your turn, Annabeth_ , said Percy's voice. But … was he speaking  _in her head_?  _Yes,_ he said, with a mental laugh.  _Come on, Annie. I know you can do it._  She shot a glare at him – she'd get him back for calling her Annie later on. But for now … She concentrated on her outstretched hands.  _Show me what you can do_ , she willed them. And then … there. She could feel a tugging in her gut, and the water started to move on her command. She laughed delightedly and spun it in a mini whirlpool around her finger, then flung herself at Percy and kissed him.


End file.
